Power Control for Compressed Mode in WCDMA System

Abstract

To perform closed loop power control, a receiving station measures the signal strength of a received signal transmitted from a transmitting station, generates periodic power control commands based on the signal strength measurements, and transmits the periodic power control commands to a transmitting station to control the transmit power level of the transmitting station. A power control filter is used to adapt the power control mechanism when the transmitting station is operating in a compressed mode to compensate for intermittent transmission by the transmitting station in the compressed mode.

1 . A method of closed loop power control in a communication station, said method comprising;
 measuring the signal strength of a received signal transmitted from a transmitting station;   generating periodic power control signals based on the signal strength measurements and transmitting said periodic power control signals to the transmitting station to control the transmit power level of the transmitting station; and   adapting a power control filter for filtering the signal strength measurements when the transmitting station is operating in a burst mode to compensate for intermittent transmission by the transmitting station in the burst mode.   
   
   
       2 . The method of  claim 1  wherein adapting a power control filter comprises varying the power control filter depending on a duty factor of said received signal in said burst mode. 
   
   
       3 . The method of  claim 2  wherein adapting a power control filter comprises varying the power control filter further depending on a burst frequency of said received signal in said burst mode. 
   
   
       4 . The method of  claim 1  wherein adapting a power control filter comprises varying the power control filter depending on a burst frequency of said received signal in said burst mode. 
   
   
       5 . The method of  claim 1  wherein generating periodic power control signals based on the signal strength measurements comprises computing a signal-to-noise ratio of the received signal based on said signal strength measurements, comparing the computed signal-to-noise ratio to a target signal-to-noise ratio, and generating power control signals based on an outcome of the comparison. 
   
   
       6 . The method of  claim 5  further comprising adjusting the target signal-to-noise ratio when the transmitting station is operating in a burst mode. 
   
   
       7 . The method of  claim 1  wherein the transmitting station comprises a mobile station. 
   
   
       8 . The method of  claim 1  wherein the transmitting station comprises a base station. 
   
   
       9 . A transceiver station for a mobile communication system, said transceiver station comprising:
 a receiver to receive a signal transmitted by a transmitting station;   a power control circuit to measure the signal strength of the received signal from the transmitting station and to generate periodic power control signals based on the signal strength measurements;   a transmitter to transmit said periodic power control signals to the transmitting station to control the transmit power level of the transmitting station; and   a control unit to adapt a power control filter for filtering the signal strength measurements when the transmitting station is operating in a burst mode to compensate for intermittent transmission by the transmitting station in the burst mode.   
   
   
       10 . The transceiver station of  claim 9  wherein the control unit varies the power control filter depending on a duty factor of said received signal in said burst mode. 
   
   
       11 . The transceiver station of  claim 10  wherein the control unit varies the power control filter further depending on a burst frequency of said received signal in said burst mode. 
   
   
       12 . The transceiver station of  claim 9  wherein the control unit varies the power control filter depending on a burst frequency of said received signal in said burst mode. 
   
   
       13 . The transceiver station of  claim 9  the power control circuit computes a signal-to-noise ratio of the received signal based on said signal strength measurements, compares the computed signal-to-noise ratio to a target signal-to-noise ratio, and generates power control signals based on the outcome of the comparison. 
   
   
       14 . The transceiver station of  claim 13  wherein the control unit further adjusts the target signal-to-noise ratio when the transmitting station is operating in a burst mode. 
   
   
       15 . The transceiver station of  claim 9  wherein the transceiver station comprises a mobile station. 
   
   
       16 . The transceiver station of  claim 9  wherein the transceiver station comprises a base station.